1. Field of the Invention
This invention relates to an exposure device, and more particularly to an exposure device and a method of fabricating a liquid crystal display panel using the same that reduces scanning frequency and improves panel production.
2. Description of the Related Art
In general, during photolithographic processes, a substance resistant to chemical etching is deposited onto a substrate or a wafer to form a photoresist layer. Then, light is irradiated onto a patterned mask that is provided above a surface of the substrate to transfer the pattern onto the surface of the substrate. During the photolithographic processes, light is irradiated onto the mask to transfer the pattern onto the substrate or wafer using an exposure device, thereby completing an exposure step.
FIG. 1 is a plan view of an exposure device according to the related art, and FIG. 2 is a cross sectional view of the exposure device along I-I′ of FIG. 1 according to the related art. In FIGS. 1 and 2, a mask stage part includes a mask 2 having a chrome pattern 16 formed thereon, and a vacuum pad 4 formed at each side of the mask 2. The pattern 16 is formed on the substrate 12 by irradiating light onto the mask 2. A pellicle 18 is positioned adjacent to the chrome pattern 16 with a specific gap formed therebetween, and a frame 14 is formed at both sides of the pellicle 18 for supporting the pellicle 18.
In FIGS. 1 and 2, an X-blade 10X and a Y-blade 10Y are positioned under the frame 14 and the vacuum pad 4 of the mask 2 prevents the light from being transmitted to areas other than the pellicle 18. The vacuum pad 4 absorbs side portions of the mask 2 with an absorber 8, and supports the mask 2 to be positioned over the substrate 12. The vacuum pads 4 are formed along each side of the mask 2 and are interconnected to each another through a vacuum line 6.
FIG. 3 is a plan view of an exposure order and exposure direction of the substrate of FIG. 2 according to the related art. In FIG. 3, the length of a shorter side of the substrate 12 located under the mask 2 is about 590 mm, and the length of a longer side of the substrate 12 located under the mask 2 is about 670 mm. In addition, the pattern on the substrate 12 is formed within a cell process key CPK that is about 576 ±2 mm, and an inspection pattern is formed along an outer area of the substrate 12 from the CPK.
If the substrate 12 included six liquid crystal display panel areas 201-206, a maximum exposure area of the exposure would be about 560 mm (in FIG. 2). However, the required exposure area of the exposure is about 576 mm for scanning and exposing the two liquid crystal display panel areas formed on the substrate 12. Thus, the two liquid crystal display panel areas cannot be scanned and exposed with a single mask 2 during one exposure. Accordingly, the exposure has to individually scan and expose each of the six liquid crystal display panel areas 201-206 formed on the substrate 12, thereby decreasing yield and increasing processing time. One proposed solution includes enlarging the frame 14 of the mask 2 to reduce the scanning frequency. However, the mask stage part is in contact with the frame 14 of the mask 2, thereby making loading problematic.
When scanning and exposing the six liquid crystal display panel areas 201-206 formed on the substrate 12 using the exposure, the nth liquid crystal display panel area is scanned along an opposite direction to the (n+1)th liquid crystal display panel area, thereby reducing a total exposure time. For example, the first liquid crystal display panel area 201 is scanned and exposed while the mask stage part moves downwards, and the second liquid crystal display panel area 202 is scanned and exposed while the mask stage part moves upwards. Similarly, the third to sixth liquid crystal display panel areas 203-206 are also scanned and exposed while the mask stage part alternately moves upwards and downwards. As a result, the first to sixth liquid crystal display panel areas 201-206 are alternately scanned upwards and downwards to be exposed and the first to sixth liquid crystal display panel areas 201-206 are scanned along the same direction to be exposed, thereby reducing total exposure time.
However, a significant decrease in picture quality often occurs in the second, fourth, and sixth liquid crystal display panel areas 202, 204, and 206, where the mask stage part moves upwards for scanning and exposing them. In addition, because the scanning directions of the adjacent liquid crystal display panel areas 201-206 are different from each other, alignment between the mask 2 and the substrate 12 should be performed a total 6 times, thereby increasing a total exposure time.